I got the following error when trying to add srv1 as the Cloudmin Services master for the new cm.cloud.virtualmin.com VM I just created there:
Checking login to services host srv1.virtualmin.com .. .. check failed : Invalid response format : syntax error at (eval 109) line 3, at EOF
It turns out this is because the user I'm trying to set it up with isn't working (when I switch it to a user that I know works, it logs in correctly). So, error is poor. Needs to explain that the user is invalid.
I also need to figure out why my new user doesn't work. Might be a misconfiguration on my part, as the UI isn't entirely obvious for creating Cloudmin users that can access Cloudmin Services.